Modify method of linking against libs. Now we fisrt try all

specified libs, and if it succeeds, we try to remove them
one-by-one. If link succeeds, then library is thrown out.
Should solve the problem with SELinux linking in libsepol
even when not needed.
This commit is contained in:
Denis Vlasenko 2007-07-17 20:39:27 +00:00
parent c5f2426838
commit 150d2fa114
2 changed files with 54 additions and 11 deletions

View File

@ -59,18 +59,25 @@ ifeq ($(CONFIG_STATIC),y)
LDFLAGS += -static
endif
BBOX_LIB_LIST = m crypt
ifeq ($(CONFIG_SELINUX),y)
LDLIBS += -lselinux -lsepol
#LDLIBS += -lselinux -lsepol
BBOX_LIB_LIST += selinux sepol
endif
ifeq ($(CONFIG_EFENCE),y)
LDLIBS += -lefence
#LDLIBS += -lefence
BBOX_LIB_LIST += efence
endif
ifeq ($(CONFIG_DMALLOC),y)
LDLIBS += -ldmalloc
#LDLIBS += -ldmalloc
BBOX_LIB_LIST += dmalloc
endif
# For scripts/trylink
export BBOX_LIB_LIST
#LDFLAGS += -nostdlib
LDFLAGS_ELF2FLT = -Wl,-elf2flt

View File

@ -6,13 +6,49 @@ try() {
added="$1"
shift
$debug && echo "Trying: $* $added"
"$@" $added >busybox.map 2>busybox_ld.err \
&& { rm busybox_ld.err; exit 0; }
"$@" $added >busybox.map 2>busybox_ld.err
}
try "" "$@"
try "-lm" "$@"
try "-lcrypt" "$@"
try "-Wl,--start-group -lcrypt -lm -Wl,--end-group" "$@"
# It failed. Let people see the error messages
cat busybox_ld.err
# Sanitize lib list (dups, extra spaces etc)
#echo "BBOX_LIB_LIST=$BBOX_LIB_LIST"
BBOX_LIB_LIST=`echo "$BBOX_LIB_LIST" | xargs -n1 | sort | uniq | xargs`
# First link with all libs. If it fails, bail out
l_list=`echo "$BBOX_LIB_LIST" | sed -e 's/ / -l/g' -e 's/^/-l/'`
echo "Trying libraries: $BBOX_LIB_LIST"
try "-Wl,--start-group $l_list -Wl,--end-group" "$@" \
|| {
echo "Failed: $* -Wl,--start-group $l_list -Wl,--end-group"
cat busybox_ld.err
exit 1
}
# Now try to remove each lib and build without.
# Stop when no lib can be removed.
while test "$BBOX_LIB_LIST"; do
$debug && echo "Trying libraries: $BBOX_LIB_LIST"
all_needed=true
for one in $BBOX_LIB_LIST; do
without_one=`echo " $BBOX_LIB_LIST " | sed "s/ $one / /g" | xargs`
l_list=`echo "$without_one" | sed -e 's/ / -l/g' -e 's/^/-l/'`
$debug && echo "Trying -l options: $l_list"
if try "-Wl,--start-group $l_list -Wl,--end-group" "$@"; then
echo "Library $one is not needed"
BBOX_LIB_LIST="$without_one"
all_needed=false
else
echo "Library $one is needed"
fi
done
# All libs were needed, can't remove any
$all_needed && break
# If there is no space, the list has just one lib.
# I'm not sure that in this case lib really is 100% needed.
# Let's try linking without it anyway... thus commented out.
#echo "$BBOX_LIB_LIST" | grep -q ' ' || break
done
# Ok, make the binary
echo "Final link with: $BBOX_LIB_LIST"
l_list=`echo "$BBOX_LIB_LIST" | sed -e 's/ / -l/g' -e 's/^/-l/'`
try "-Wl,--start-group $l_list -Wl,--end-group" "$@"